Quality of life and immune activation in patients with HIV-infection

Depression and impaired quality of life (QoL) are frequently observed in patients suffering from HIV-infection. As an enhanced degradation of the serotonin precursor tryptophan is well documented in HIV-infected patients, disturbances in tryptophan metabolism may be causally linked to HIV-related depression. In this study, the relationship between QoL, depression, various laboratory parameters and tryptophan metabolism was investigated. To estimate QoL and mood, 152 HIV-infected patients (classified according to CDC-criteria) were requested to complete the following psychological questionnaires: BDI and MQoL-HIV. Disease progression was monitored by determination of viral load (VL), CD4(+) cell counts, haemoglobin and urinary/plasma neopterin, tryptophan and kynurenine concentrations. Increasing VL, decreasing CD4(+) cell counts, and enhanced tryptophan degradation reflected disease progression. Forty-one patients presented with mild, 22 with moderate and 14 with severe depression. BDI and MQoL scores were associated strongly with each other (rs=-0.838; p<0.001). Patients without depression had significantly lower plasma neopterin concentrations, higher CD4(+) cell counts and haemoglobin concentrations and better QoL scores (all p<0.01) than depressive patients. Furthermore, they showed lower rates of tryptophan degradation (p<0.05). Significant associations were observed between tryptophan degradation and immune activation. Haemoglobin and viral load were predictive for impaired QoL, while high urinary neopterin concentrations and low haemoglobin were the best predictors for depression. In HIV-infected patients, depressive mood and impaired QoL appear to be related to clinical parameters like immune activation, haemoglobin values and viral load.